FR love quoting them and yes they are high, but surely very few passengers actually book and travel BA on them, with most just booking a return and not using the return portion.
So Fr's comparison is a red herring, why don't they compare high return fares with carriers that still require a saturday night stay for good return fares, LH for example.

FR is comparing a one-way price with a one-way price. If it was a one-way price verses a return price, then that would not be as accurate, even if it was cheaper. It clearly says it’s only comparing one-way fares, so all is fine.

It is normally impossible to give a like-for-like example (BA might not serve the same airport which FR does), so the comparison is a little inaccurate, but it does the job pretty well.

Let’s pretend I want to fly ONE-WAY between Glasgow and Rome on 1st June and could choose either FR or BA. Consider the following:

BA – GLA to FCO via LHR. The total fare, inclusive of tax, is £560.60.

FR – PIK to CIA. The total fare, inclusive of tax, is £51.18.

A bit of a difference, I think you’ll agree, not only in price but also in travel duration.

Even if we unfairly compare a one-way fare with a return (returning on, say, the 7th), then BA's still substantially more expensive:

"But comparing more likely scenarios is more useful, practical and credible."

Perhaps, but the average punter isn't likely to know that a roundtrip is less expensive. Also, comparing a one-way fare with a roundtrip fare is neither as good and as illustrative for FR as a one-way vs one-way comparison. If I was the CEO of FR, I'd be doing exactly the same thing, as it would show my firm in a better light.

"Everyone writing for the Telegraph knows that the way to grab eyeballs is with Ryanair and/or sex."